POS1094 CORRELATION OF FLUORESCENCE-OPTICAL IMAGING AND PHYSICIAN TJC/SJC ASSESSMENT AND ULTRASOUND IN PSORIASIS PATIENTS WITHOUT ARTHRITIS BUT MUSCULOSKELETAL COMPLAINTS WITHIN THE LAST 6 MONTHS
Authors: M. Köhm, S. Ohrndorf, X. Baraliakos, K. Hallmann, S. Kempinski, A. C. Foldenauer, T. Rossmanith, U. Henkemeier, F. Behrens
Journal: Annals of the Rheumatic Diseases (2022)

Background Psoriasis (PsO) is one of the most common chronic inflammatory skin diseases in Europe. Psoriatic arthritis (PsA) is closely associated to PsO; up to 40% of PsO patients develop PsA. The transition from PsO to PsA includes different stages with unspecific clinical symptoms such as fatigue or musculoskeletal (MSK) symptoms as well as changes in synovial vascularization combined with increased expression of proangiogenic factors [1]. Fluorescence-optical imaging (FOI, [Xiralite]) is an easy-to-use method to detect changes in microvascularisation of the hands. Objectives To compare findings from FOI assessment to clinical examination (SJC/TJC) and musculoskeletal ultrasound in patients (MSUS) with non-specific MSK-symptoms and changes in microvascularisation without evidence of clinical active PsA. Methods The German multicentre observational XCITING study recruited patients with dermatological confirmed PsO at risk for development of PsA (either nail psoriasis or MSK symptoms such as joint pain or swelling within the last 6 months). Clinical examination (CE; swollen (66) and tender (68) joint count, enthesitis, dactylitis assessment), standardized MSUS and FOI assessment were performed by a qualified rheumatologist at one time point with focus on the question of presence of PsA. Data were analyzed in focus on increased vascularization of MSK structures of both hands as marker of inflammation. The patients at-risk for PsA development but without clinically active PsA (CE negative, FOI positive) were analyzed. Results from CE of joints, MSUS and FOI were compared. Results 391 PsO patients were recruited for the XCITING study in total. 108 patients (27.6%) were identified as at-risk population (CE negative, FOI positive). Baseline characteristics included a mean age of 51.4 years (SD 11.3), 61.1% female, mean BMI 27.8 kg/m2 (SD 5.2), mean age of onset PsO 30.4 years (SD 17), mean duration of PsO of 16.9 years (SD 14.4), mean PASI 4.3 (SD 5.8) and mean patient’s global disease activity for PsO of 24.4mm (SD 21.1). In 24.1% psoriasis plaques on the hand were documented. Pattern for frequency of scores in FOI, CE and MSUS in the dominant hand were compared (Figure 1). Frequency of swollen joints and synovitis with power Doppler activity (PD Mode) was very low in these patients whereas TJC, detection of synovitis in MSUS and FOI signals were detected in overlapping regions at the hands, showing high correlation. The highest correlation is found between TJC and FOI (Figure 1). Figure 1. Overview of frequency of involvement in joints for the different assessments (MSUS, SJC/TJC and FOI) Conclusion FOI signals in the hands correlate to the findings of TJC (and B-Mode US) in the clinical examination indicating early stages of MSK inflammation that may result in active PsA development. FOI as standardized and easy-to-use technique might be a suitable tool for early detection of PsA in Psoriasis population. A follow up in these patients will reveal prediction values of the method. References [1]Scher, J.U., et al., Preventing psoriatic arthritis: focusing on patients with psoriasis at increased risk of transition. Nat Rev Rheumatol, 2019. 15 (3): p. 153-166. Disclosure of Interests Michaela Köhm Grant/research support from: Pfizer, Sarah Ohrndorf: None declared, Xenofon Baraliakos: None declared, Konstantin Hallmann Grant/research support from: Pfizer, Susanne Kempinski: None declared, Ann Christina Foldenauer Grant/research support from: Pfizer, Tanja Rossmanith Grant/research support from: Pfizer, Ulf Henkemeier Grant/research support from: Pfizer, Frank Behrens Grant/research support from: Pfizer